Bug Description

Forgive me if this bug is a duplicate but I didn't see a recent bug with these details.... I did a clean install of Kubuntu 10.04 beta 2 and i noticed the wireless connection would work initially after boot and then it would drop and then tray icon would continue to say "Connecting" and "Activating" when i right clicked on it and never connect again. I did get it to reconnect once after unloading the iwl3945 and iwlcore modules and reloading them, then restarting the networking init.d script, but that only worked once, every other time i had to reboot for it to work again. Most recently though i connected it and left it on overnight and it stayed connected fine the whole time (i had received IMs meanwhile) and i was able to browse through gmail and the web fine but as soon as I went to a YouTube link it died right away. So then i installed the mainline kernel version: 2.6.34-999 from http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/current/ and tried the same YouTube link and everything works fine.

Previous kernel versions I was using that had the problem:
2.6.32-19
2.6.32-21

Please be sure to confirm this issue exists with the latest development release of Ubuntu. ISO CD images are available from http://cdimage.ubuntu.com/releases/ . If the issue remains, please run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux 564376

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

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I can confirm that I am affected by this bug as well. It is extremely easy to reproduce and it makes the wireless connection all but unusable.

I have run the apport-collect command suggested above and the report should be attached to this bug now. Since the 10.04 LTS is so close now I have marked this as regression-release. I haven't seen this bug with the latest 2.6.31 kernel found in 9.10, or with any other kernels in previous distributions. This behavior started occurring when I upgraded to 10.04 RC three days ago.

In my case, it appears that the bug manifests whenever there is high traffic over the wireless connection, but it is more prevalent when said traffic is generated by streaming video within a browser (I've tried with YouTube and a number of other streaming video websites). Most of the times, the adapter will disconnect within 30 seconds of starting streaming and sometimes it will reconnect immediately afterwards. In other cases, this will take longer to reconnect (ahem, I haven't waited more than a minute or so before disabling and re-enabling the adapter, which seems to speed up the reconnecting process).

When the adapter disconnects, the kernel log shows the messages attached to this post. Note that this particular occurrence resulted in a quick reconnection, but this didn't make it any less annoying.

I forgot to mention that, unlike the original poster (Nick), installing 2.6.34-999 did not solve the problem for me - in fact, it made it worse (a subjective opinion, since this is not easily measurable). I have also installed linux-backports-modules-wireless-lucid-generic, to no avail. I will try installing a mainline kernel that is closer to the one currently running (per http://kernel.ubuntu.com/~kernel-ppa/info/kernel-version-map.html) and I will get back with details.

All right, I've tested 2.6.32.12-lucid and 2.6.33.3-lucid (plus 2.6.34-999, April 25th edition, which I tried two days ago) hoping that upstream may have fixed this. Unfortunately, the bug is still present and, in addition, I could not extract any kernel logs because (see attachment). All in all this adds up to three very recent mainline versions having the same issue as far as iwl3945 is concerned.

With 2.6.32.12-lucid, I also saw what may have been an isolated occurrence, but the kill switch didn't work either, meaning that disabling and re-enabling the wireless adapter had no effect and I had to reboot in order to have my wireless connection working again.

Any input on this would be greatly appreciated. I remember finding something very similar two days ago on the Intel Bugzilla for iwl3945 but somehow (ahem) I forgot to save the reference and I can't seem to be able to locate it again.

In support of the idea that this bug is a regression, I installed and tested the mainline 2.6.31.12 kernel, which is what the latest kernel in koala was based on. Surely enough, the bug *does not* manifest with the older kernel.

I've done some more testing on this bug and I came to a surprising conclusion - at least for me.

I've been thinking about the weird behavior this bug exhibited. Initially I thought that it was about high traffic on the wireless interface. Then, I realized that this was not really the case - as I did some heavy wgets and nothing went wrong with those. This bug seems to only show up when high video activity is present as well (this explains why it manifests with streaming video).

The more I'm thinking about it, the more I lean towards some sort of IRQ conflict between iwl3945 and radeon (note that the original poster also had a Mobility Radeon video adapter). Anyway, thinking about how KMS created all sorts of issues for lucid, I went ahead and disabled it (radeon.modeset=0) with 2.6.32-21-generic (the current lucid kernel).

Lo and behold, the wireless adapter does not lose connection anymore (I've been abusing it for the past hour now).

This could also explain why this bug doesn't affect so many people - if it requires that *both* iwl3945 *and* radeon be present, the subset of users that have this particular hardware combination should be somewhat smaller.

I was seeing this bug in the betas, too. Last night (because of another issue, with X not loading and a bunch of radeon errors) I did a clean install of Lucid, and disabled KMS (to fix my weird X errors; I didn't know it was related to the wireless), and I haven't seen the bug yet this morning.

1) Youtube (or Flash in general) fullscreeen => iwl3945 very often drops the wireless connection during streaming (usually accompanied by some timeout errors in log, and sometimes even hpet "increasing min_delta_ns" warnings).
2) Fullscreen video or Flash => pops/crackles in audio, even though system is *not* overloaded (and this is *not* caused by Pulseaudio or HDA power management).
3) Running neverball under KMS actually causes dropped wireless connection, it seems (this happened with 2.6.34-rc7)..

I've been investigating audio issues under KMS for many days since I installed Lucid, since I have problems with crackling noise during video playback. Radeon KMS somehow causes problems with snd-hda-intel interrupt handling (been at it in bug 15912 at bugzilla.kernel.org, for a few days now).

Tried 2.6.34-rc7 (compiled myself from mainline, but using Ubuntu packaging and config), and after getting some other audio issue fixed (in same kernel bug metioned above), the pops/clicks and wireless problems sadly remain when using KMS.

Disabling radeon KMS definitely causes all audio problems to vanish, but I have not verified if it also cures the wireless problem with iwl3945.

The wireless connection typically stays up during normal size Flash video streaming, but drops a short while after entering fullscreen, somehow relating it to system load or "graphical load". Perhaps it's some timing issue.

As per Stejarel Veres I changed Added radeon.modeset=0 and I played variety of big video files 1080p, 720p quality and also in fulscreen which I did play for almost more than hour. I never had a connection drop once. I am happy about it now.

Regarding the bug #577537 which is a duplicate of this needs to be closed.

I see the same problem on AMD platform with Radeon X1250 (integrated/chipset) and Broadcom BCM4312 wireless card using b43 open source driver. So this problem is not only related to a Intel 3945ABG wireless card. Tested radeon.modeset=0 and the problem vanished so far.

I posted on the Phoronix forums to try to attract some of the radeon driver devs to this problem directly, and linked to this bug report for their reference. Several of the radeon developers participate there, so I thought it might help.

Several Launchpad bug reports in process report radeon KMS conflicts with Intel wifi and audio output, causing wireless to hang/drop until power cycle and audio to crackle during any high GPU load. Disabling KMS as a workaround returns normal system operation.

My own hardware is a Thinkpad T60 with Radeon X1400 and Intel wireless (iwl3945 driver) running vanilla Ubuntu 10.04. Users of Radeon X1250, X1300, and Xpress 200M chipsets have also reported the same behavior, on Lenovo, Dell and LG laptops. Using a mainline kernel does not change the behavior.

This may possibly be due to a difference in PCI configuration between KMS and UMS, they use different IRQs for "Pin A" as detailed in the Bugzilla report linked above.

Thanks for any assistance you can provide! And thanks for all your hard work!

When I disable radeon KMS I get stronger wireless signals and am able to connect to networks I could not previously (network manager reports 88% connection strength when previously I would get 1 bar and then the connection would be lost)

Confirming this one, Thinkpad Z61m, ATI X1400. However, the IRQ difference does not seem to matter for the audio problems (I've tested with radeon KMS both with and without MSI, which is the difference between the two PCI configs listed in bug at https://bugzilla.kernel.org/show_bug.cgi?id=15912).

I don't think it is directly an IRQ issue that can be solved in the BIOS.
Because on my girlfriend's laptop which is also hit by this problem the radeon takes IRQ 17 with IO-APIC-fasteoi and hda_intel takes IRQ 24 with PCI-MSI-edge

(In reply to comment #44)
> Created an attachment (id=47928) [details]
> Kernel log while loading the radeon driver
>
> With kernel 2.6.39 I get the NMI message (see attachment) on every boot while
> the radeon driver is loaded. With earlier versions this happened only while i
> switched the console.
>
> Maybe it would help to investigate the module loading?
> If anyone can tell me how to do that, i can submit more detailled informations.
>
> Thanks,
> jan.

I've added dmesg output from Ubuntu 11.04 which is not affected with the bug (at least on my laptop - Thinkpad T60, 2623P2U, X1300) and Fedora 15 which does have the problem. Unless I missed something, the only relevant difference is DRM version reported, which is 2.8 for Ubuntu and 2.10 for Fedora (how come that's possible is another question).
So far, the following does not help:
- disp_priority=1
- agpmode=1
- gartsize=64
- dynclks=0

I played a bit with power_profile settings and it turns our that whenever profile is set to high, mid, sound stuttering is pronounced. Yet, once set to low, stuttering is gone (or unnoticeable).
If anyone wants to try (adjust path to suit your hardware):
echo low > /sys/class/drm/card0/device/power_profile
Then the actual frequency can be verified by:
cat /sys/kernel/debug/dri/0/radeon_pm_info

Also dynpm power_method does not really work, there was another bug report recenty that the frequency is never lowered if dynpm is used.

Additionally, given the recent fuss about pcie_aspm=force (and possible effect on PCIe), sound stuttering is present regardless of the setting.

(In reply to comment #50)
> I played a bit with power_profile settings and it turns our that whenever
> profile is set to high, mid, sound stuttering is pronounced. Yet, once set to
> low, stuttering is gone (or unnoticeable).
> If anyone wants to try (adjust path to suit your hardware):
> echo low > /sys/class/drm/card0/device/power_profile
> Then the actual frequency can be verified by:
> cat /sys/kernel/debug/dri/0/radeon_pm_info

Confirming this on ATI X1400 mobile, Ubuntu 11.04 x86. When using the "low" power profile, audio stuttering/crackling is much less prevalent (or maybe not even noticable) in Youtube fullscreen vids. Using the "high" setting results in definite audio crackling when switching to fullscreen. This is with the very latest Flashplayer 11 beta for Linux released today.

(In reply to comment #51)
> There's a difference not only in board frequencies, but also the PCIE lanes
> number (0 means full throttle, or is "more performant" than 1 I guess ??).

The PCIe lanes information seems to be read from the card itself (at least that's for RV515), look here:http://lxr.linux.no/#linux+v2.6.39/drivers/gpu/drm/radeon/r300.c#L553
While 1 is understandable (PCIe x1), 0 value is confusing and I can't tell if that'x x16 or not. Maybe one of the driver authorsa can provide some input.

I've failed to locate any docs that contain information on the registers exposed on the PCI.

I'd like the importance of this bug being corrected to 'major' because disabling KMS in fact means a major loss of functionality. I'm now on kernel 2.6.40 and sadly this heavy bug still is there.

I skipped form Windows to Linux, mainly because the ATI Driver for the x1400 in my Thinkpad T60 (with iwl3945 od course) is crap.Now having tried many different distributions and kernels, i can confirm the bug still is there, and is making the notebook unusable. There's no 3D acceleration available at all on this GPU with KMS disabled. When playing a flash video it needs about 30 seconds fpr reaction if I clock some control with the mouse. Compiz or DirectX in Wine aren't working at all, and make the display crash. The GPU is wasting much energy and the notebook is running very hot, and overall just sluggish and not enjoyable in any fashion, I'd rather use my old Pentium M notebook, if it wasn't defective.

Please consider creating a solution fot this problem, as there's no single alternative for many Notebook owners, of expecially good notebooks (Thinkpad, Dell and more).

Problems with KMS enabled remain as before:
-iwl3945 WLAN gets slower and slower, until disconnect.
-heavy video (especially fullscreen) make the sound stutter in a fashion that makes it impossible to understand spoken word

Seems worse than ever on Ubuntu 11.10 just released (kernel 3.0, libdrm 2.4.26, xserver 1.10.4, using the new Unity-interface-thing). Just moving the mouse pointer is enough to disturb audio now, apparently. And moving windows around turns audio into bubbling porridge.

Unity is sluggish on the X1400. Guess it's too old to cope now, with the latest desktop tech. Anyways, audio interruption is more or less constant after a while. Don't even need to move anything. Got these:

(In reply to comment #57)
> Unity is sluggish on the X1400. Guess it's too old to cope now, with the latest
> desktop tech.
Not really. Worked great with UMS. Compiz with way more advanced effects than fade in/out was smooth, same for ioquake running at decent framerate.

Jan Kouba put me on track to this bug-page. I don't know if "official" developers use this channel as a information or judgment source of bugs. As far as I know Ubuntu works on launchpad to administrate bugs.

For this problem I created https://bugs.launchpad.net/ubuntu/+bug/879790 in order to make Ubuntu know that problem. It may be an idea to "make some noise" there in form of clicking on the button "This bug affects...". And - if you feel like - to reproduce some of your statements from this bug-report-page. Hopefully they will take notice finally.

With a new enough kernel, you can disable MSIs on radeon by setting radeon.msi=0 on the kernel command line in grub or when you load the module. You can disable MSIs globally by setting pci=nomsi on the kernel command line in grub.

I tried to git the 11.10 package from ubuntu and recompile with the change you mentioned in rs600.c file and r100.c . It didnt seem to help. I noticed someone tried disabling MSI so this might not be related to MSI at all...

Has anyone tried messing with the audio or wifi drivers? It's possible the issue is on that side. How about messing with the cpufreq governors? Is it still an issue if you force the cpu power state to performance, etc.?

The wifi I tried disabling the sound quaility is still bad when doing anything display intensive. I havent tried disabling alsa altogether to see if the wifi is still dropping..

I wanna say when I first come up with MSI fixed version it sounds fine, youtube also sounds normal, but if I make the unity taskbar show up, then it goes into some sort of bad state where sound is bad again..maybe the clock switch in the gpu clock or cpu? Not sure....

Apologies if this is not strictly on topic regarding fixing this bug - what I'm curious to know is what the 'best case' workaround all of you are using to avoid this problem? I'm open to absolutely any distribution, desktop environment, etc. Just wondering what the best alternative many of you have found to avoid the conflict and maintain the most functionality.

My best case options so far: Ubuntu 10.04 LTS where I don't remember noticing this problem, or even 12.04 in 2D if I could get my volume control buttons to work on my Thinkpad t60.

I'm also playing with arch to see if I can build something usable I like.

I have been able to get around this bug on IBM T60/x1400 running Kubuntu 12.04, by using kwin_gles desktop manager instead of the default one (kwin).

I had problems with sound slowing down and being very choppy when desktop effects were enabled, or when playing full-screen flash videos. I did not notice any problems with wifi. With kwin_gles I have absolutely no sound issues with desktop effects enabled.

I'm not X expert, so please take the following lines as my humble opinion. I belive, that the workaround is caused by the fact, that kwin_gles uses EGL for rendering, while kwin uses GLX. So maybe this bug can be avoided on other distros and window managers by setting them to use EGL instead of GLX.

Just for the record I've tried Kubuntu 12.04.02 and the kwin_gles workaround does _not_ work for me unfortunately(T60 w/ X1400) . There are still messages like "CE: hpet increased min_delta_ns to 20113 nsec", and the wireless is very slow. This issue is very frustrating and is the first time when the open source model fails to work for me. I mean this report was filed 3 years ago, affects thousands of people, there is no good workaround and yet no one from the "radeon" developers seems to care.
I wonder if we can raise money and put together a bounty or something...

@Alex Deucher: Yes, the modern operating systems and hardware are complex beasts and I surely understand that some bugs may be hard to track down. The point is however that there wasn't a systematic effort to resolve this particular issue except for some "there is a random problem X described in ticket Y, which may be the reason for your troubles too, so why don't you try the solution proposed there". By the way I tried the change proposed by Michel Dänzer in https://bugs.freedesktop.org/show_bug.cgi?id=38694 , but unfortunately it doesn't seem to help either.
I am clueless about the kernel internals, but the manifestations of this bug seem to be consistent with the hypothesis that there is something wrong with the "radeon" driver. It seems like something locks the system for long periods of time and the other time sensitive modules "freak out". On my laptop the problem became even more pronounced when I swapped the "1440x900" LCD panel with a "1600x1200" one.

(In reply to comment #76)
> @Alex Deucher: Yes, the modern operating systems and hardware are complex
> beasts and I surely understand that some bugs may be hard to track down. The
> point is however that there wasn't a systematic effort to resolve this
> particular issue except for some "there is a random problem X described in
> ticket Y, which may be the reason for your troubles too, so why don't you
> try the solution proposed there". By the way I tried the change proposed by
> Michel Dänzer in https://bugs.freedesktop.org/show_bug.cgi?id=38694 , but
> unfortunately it doesn't seem to help either.

There were several suggestions on this bug, but apparently none of them helped.

> I am clueless about the kernel internals, but the manifestations of this bug
> seem to be consistent with the hypothesis that there is something wrong with
> the "radeon" driver. It seems like something locks the system for long
> periods of time and the other time sensitive modules "freak out". On my
> laptop the problem became even more pronounced when I swapped the "1440x900"
> LCD panel with a "1600x1200" one.

A bigger display means more data is being moved around. It sounds to me like a chipset issue when large amounts of data are being transferred across the bus. KMS uses system memory more readily than UMS did which is likely why the issues shows up with KMS. I don't know of any other options to try in the driver. We don't have these problems with the same radeon chips is other systems. Unfortunately, I'm not a chipset expert so I'm not sure what sort of pci quirks, etc. to try.

It could also be that the there is an issue in the sound or wifi driver which didn't show up as readily when there was less traffic on the bug. As far as I know no one has investigated these avenues very much.

Background: For two years I've been experiencing strange, yet increasing problems with Kubuntu on my ThinkPadsT60/T60p. It started with version 10.10 which suffered from strange WLAN faults and random desktop lockups. The workaround for the WLAN problem slowed the wireless interface down so much that is was unusable.

Since version 11.10 a problem with my USB keyboard came on top: Every now and then - but still regularly - the key last pressed was repeated endlesslyyyyyyyyy. And versions 12.04 and 12.10 also had the sound problem also experienced by others. The sound was distorted so much that listening to music and watching videos was impossible. The distortions were even worse in full screen video. The GUI ran quite slow and lagged (even on my 2.1 GHz machine).

A step in the right direction was the GLES window manager on my 12.04 Kubuntu. It worked fine fixing all these problems but was not very fast. Kubuntu was usable again at the price of less fun using the system. But Kwin GLES only works with Kubuntu up to version 12.04(.01), not version 12.10. In the latter the screen refresh is faulty which makes using the desktop impossible.

So I was keen on testing the new Kubuntu 13.04 released last week. During the weekend I had the chance to use it quite extensively on a fresh installation and -
all problems with WLAN, keyboard, sound and speed are gone now. The new Kubuntu is the best version available for my ThinksPads - fast, stable and without the sharp edges previous versions had.

Ubuntu 13.04 x86 was as bad as ever on old Thinkpad Z61m (tested with live CD, default Unity env). None of the problems with KMS+audio+wireless are fixed. Luckily I don't use that laptop much nowadays.

ndeubert, this bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? If so, could you please test for this with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in the development release from a Terminal (Applications->Accessories->Terminal), as it will automatically gather and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Please do not test the daily kernel folder, but the one all the way at the bottom. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.11.1

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

I had all the problems as described by Øyvind Stegard and I have the feeling that it got slightly better after installing the latest available BIOS for my Thinkpad T60 2007-CTO (ATI X1400, iwl3945, snd-hda-intel).

I've tried all other options mentioned here, without any sign of improvement. What can I do to further help investigating this problem? Would it be of any help to e.g. study the IRQ settings used in windows?

ndeubert, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/linux/+bug/564376/comments/133 regarding this being fixed with an update. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.